The present invention relates to the field of lighting devices and more particularly to methods of controlling a lighting device including a plurality of light sources.
The present application incorporates by reference the application titled xe2x80x9cImprovements to Lighting Devices Using a Plurality of Light Sourcesxe2x80x9d filed on Mar. 15, 2000, Ser. No. 09/526,599.
When using a lighting device to illuminate an area it is often found necessary to alter the beam of the projected light to provide control over the color or focus. For example often a flashlight might be equipped with a means for changing the profile of the emitted light beam from a spot to a wash.
U.S. Pat. No. 4,855,884 to Richardson discloses a variable beam width stage light with a single light source, relying on an axially movable reflector for changes in beam width. The reflector is constructed of a plurality of reflective leaves that are moved by a motor to change the focal length of the reflector. U.S. Pat. No. 4,729,070 to Chiu discloses an adjustable ring for concentrating multiple beams of light. Chiu discloses an apparatus for changing the angle of incidence of a plurality of light sources arranged in a ring. A threaded holder surrounds the ring of light sources while a cam mechanism adjusts the angle of the light sources that is operated by turning the threaded holder. U.S. Pat. No. 5,752,766 to Bailey et al. discloses a multi-color focusable LED stage light. A linear actuator is operable to move a base member containing an array of LEDs which in turn cause the LED array to change the direction of the optical axes of a substantial number of LEDs. By deforming the base member 20 in Bailey, the LEDs can be converged or diverged on an area to be illuminated.
Multi-parameter lights of the prior art utilize a single light source with mechanisms driven by motors to vary the focus, color, position and intensity. U.S. Pat. No. 3,845,351 to Ballmoos et al. titled: xe2x80x9cMETHOD AND APPARATUS FOR THE ADJUSTMENT OF A PLURALITY OF FLOODLIGHTSxe2x80x9d discloses a number of floodlights especially for the illumination of a stage or studio, in which the parameters azimuth, elevation, brightness, focus and color of a bundle of light rays of each floodlight are adjusted to an optimum value for any one of a plurality of lighting effects.
U.S. Pat. No. 4,392,187 to Bornhorst titled: xe2x80x9cComputer controlled lighting system having automatically variable position, color, intensity and beam divergencexe2x80x9d illustrates another example of the prior art. Each of the instruments houses a central lamp and an optical system designed to collimate the light from the lamp and vary the parameters of the light by inserting motor driven optical components into the light by remote control.
Multi-parameter lights are generally controlled by a central control system via a serial data communications system. An operator operating the central control system may control each multi-parameter light separately to adjust the parameters. Each multi-parameter light may be provided with a communications address so that each multi-parameter light may be addressed separately by an operator operating the control system.
Multi-parameter lights of the prior art are depicted in a HIGH END SYSTEMS (trademarked) Product Line 1997 brochure. It is known in the art to construct a lighting device using a plurality of light emitting diodes (LEDs) such as disclosed in U.S. Pat. No. 5,752,766 to Bailey et al.
U.S. Pat. No. 5,652,766 to Bailey et al. titled xe2x80x9cMulti-color focusable stage lightxe2x80x9d and is incorporated by reference herein describes an LED stage lighting instrument constructed of arrays of red, blue, and green LEDs.
The red, blue and green LEDs are operated in an additive color system to produce various colors of light by mixing the primary colors of red, blue and green together in various combinations. In my pending application entitled xe2x80x9cIMPROVEMENTS TO LIGHTING DEVICES USING A PLURALITY OF LIGHT SOURCESxe2x80x9d, filed on Mar. 15, 2000, Ser. No. 09/526,599 describe some of the disadvantages of constructing a lighting device using discrete spectral LEDs of Red, Blue and Green. When creating white light through the use of an additive color system using red, green and blue wavelengths (RGB), the spectral energy adjacent to the red, green and blue wavelengths is usually omitted. An RBG system used to create white light can sometimes be problematic when illuminating objects that absorb or reflect very specific wavelengths of light. Illuminating these types of objects with RGB derived white light often may result in an erroneous perception of color by the viewer as compared to viewing the object under continuous spectrum white light.
Broad-spectrum visible white light emitting diodes such as those manufactured by Nichia Chemical Corporation of Japan can be used to produce a lighting device that produces white light without using the discrete spectral LED""s used in a color additive system. The term xe2x80x9cwhite light LEDxe2x80x9d refers to a light emitting diode that provides a spectrum that is seen by the human eye for all purposes as white. One disadvantage is that the device constructed of exclusively white light LED""s cannot produce colors without placing a color filter in the path of the projected light. Placing a single filter over a plurality of white light LED""s can be accomplished but as the array of white light LEDs increases in numbers the filters become quite large.
U.S. Pat. No. 5,652,766 to Bailey discusses the use of a flexible base member to change the focus of a plurality of red, blue and green LEDs with an LED stage light. My co pending application, Ser. No. 09/526,599 discussed the use of a variable filter that may be a liquid crystal emulsion filter mounted after the light sources. Changing the voltage to the filter causes the light from the light sources to pass through the filter deflected or undeflected depending on the voltage state. The above methods alter the projected light from a narrowed angle to a wider angle by varying the diffusion of the light or by redirecting the individual light sources to a different emitting angle.
In one embodiment of the present invention, an apparatus is provided comprising a substrate having a first light source and a second light source mounted thereon and an aperture device having a first aperture and a second aperture. The aperture device can be aligned over the substrate so that light from the first light source is emitted through the first aperture and light from the second light source is emitted through the second aperture. The first and second light sources may be light emitting diodes.
The aperture device may be comprised of third and fourth apertures. In one embodiment the aperture device can be aligned over the substrate so that light from the first light source is emitted through the third aperture and light from the second light source is emitted through the fourth aperture. The aperture device may be comprised of an aperture plate which includes the first and second apertures. The aperture plate may be round. The aperture device may be rotationally mounted centrally over the substrate.
Each of the light sources may emit a broad-spectrum visible white light. The aperture device such as an aperture plate may be comprised of a transparent material. The substrate with the light sources mounted thereon and the aperture device may be built into a multi-parameter lighting device or into a flashlight.
Generally a plurality of light sources may be mounted to the substrate. Generally, an aperture plate may be provided with a plurality of apertures that are strategically aligned with the individual light beams emitted from each of the plurality of light sources. There may be a set of apertures for each individual light beam. The aperture device may be referred to as a beam altering mechanism for altering the light projected by the plurality of light sources. The present invention, in various embodiments, may be included in hand held flashlights, theatrical lighting, and may have other applications. Theatrical lighting is used in concerts, special events, nightclubs, television studios, restaurants and theme parks.
The beam altering mechanism (which in one form includes an aperture device) can be capable of changing the color of the emitted light beam produced by for example, a flashlight. In one embodiment additional apertures containing color modifying filters are also strategically placed in the aperture device (or aperture plate) and these modifying filters can be aligned over each of the light sources by rotation of the aperture device, such as an aperture plate.
Access for rotating the aperture plate by the user, in a flashlight embodiment for example, is accomplished by allowing at least part of the aperture plate to protrude from a housing of the flashlight. It is preferred that the plurality of light sources are arranged symmetrically to provide uniform illumination.
In another embodiment of the present invention the aperture device, which may be an aperture plate, is arranged with a plurality of apertures that contain light refractive optics that are strategically placed in the aperture device and provide a means for changing the focus of the overall beam (sum of the light beams from the individual light sources) produced by the flashlight. It is possible that the invention in one or more embodiments could be used to change most of the light beam emitted by the lighting device but the light from one or more LED""s may not be changed. Allowing some LEDs to remain unchanged can provide a mixture of white and colored light producing more pastel colors. For an aperture plate with light refractive optics allowing some LEDs to remain unchanged may provide desired differences in the overall profile of the light beam emitted by the plurality of light sources.
A further embodiment of the present invention discloses a remote controlled lighting device incorporating a plurality of light sources and a beam altering mechanism capable of altering the beam of the projected light from each of the light sources. The beam altering mechanism can be comprised of an aperture device, such as an aperture plate, provided with a plurality of apertures that are strategically aligned with the individual light beams emitted from each of the plurality of light sources.
In one embodiment of the present invention, the aperture plate is round and is centrally and rotationally mounted to a shaft connected to a stepping motor. In this embodiment the stepping motor can be capable of remotely rotating the aperture plate into a position. The light sources can be arranged symmetrically to provide uniform illumination.
In another embodiment of the present invention the aperture device is arranged with a plurality of apertures that contain light refractive optics that are strategically placed in the aperture plate and provide a means for changing the focus of the beam produced by the lighting device. A masking device, which may be a masking plate, may also be provided in one embodiment.